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The first and asymmetric total synthesis of cyclocitrinol, an unusual C25 steroid, has been accomplished in a linear sequence of 18 steps from commercially available compound 11. The synthetically challenging bicyclo[4.4.1] A/B ring system with a strained bridgehead (anti-Bredt) double bond of cyclocitrinol was constructed efficiently and diastereoselectively via a type II intramolecular [5 + 2] cycloaddition.

A type II intramolecular oxidopyrylium-mediated [5+2] cycloaddition reaction allows the efficient and diastereoselective formation of various highly functionalized and synthetically challenging bridged seven-membered ring systems (such as bicyclo[4.4.1]undecane, bicyclo[4.3.1]decane, bicyclo[5.4.1]dodecane, and bicyclo[6.4.1]]tridecane). This simple, thermal, direct transformation has a broad substrate scope and is high yielding, with high functional-group tolerance and unique endo selectivity. The highly strained tricyclic cores of ingenol mebutate (picato) and cyclocitrinol are synthesized efficiently and diastereoselectively using this methodology.

The concise total synthesis of aplykurodinone-1 with an unusual cis-fused hydrindane moiety has been accomplished without the need for any protecting group chemistry using a unique SmI2 mediated reductive cascade cyclization reaction and a direct cuprate mediated 1,4-addition. This work represents the first example of the use of a SmI2-mediated intramolecular cascade cyclization reaction between "halide, alkene and aldehyde" groups.

The first dearomative indole [5+2] cycloaddition reaction with an oxidopyrylium ylide resulted in efficient and diastereoselective construction of some highly functionalized and synthetically challenging oxacyclohepta[b]indoles. The protocol proceeds under very mild reaction conditions, thus enabling high functional-group tolerance and unique endo selectivity.

Treatment of 3-(4-carboxyphenylhydrazono)pentane-2,4-dione (HL) with transition metal ions afforded four novel complexes, [Zn(L)( μ 2 -OOCCH 3 )(H 2 O)] n ( 1 ), [Zn(L) 2 (MeOH) 4 ] ( 2 ), {[Cd 4 ( η 2 -L) 4 ( μ 2 - η 2 -L) 4 (H 2 O) 4 (MeOH) 2 ]·MeOH} ( 3 ) and [Cd( η 2 -L)( μ 2 - η 2 -OOCCH 3 )(H 2 O) 2 ] n ( 4 ). Their crystal structures have been characterized by single-crystal X-ray crystallography. In polymer 1 , the acetate anions bridge the Zn(II) ions forming an infinite one-dimensional (1-D) chain with L − units acting as monodentate ligands in the side chain. In mononuclear complex 2 , two L − ligands act as monodentate fashion to coordinate to the Zn(II) ion. In its solid-state structure, [Zn(L) 2 (MeOH) 4 ] groups are joined together by hydrogen bonds forming a three-dimensional (3-D) supramolecular network. In tetranuclear complex 3 , four Cd(II) ions are linked by four μ 2 - η 2 -L − ligands, and chelated by another four L − ligands, respectively. In polymer 4 , the acetate anions bridge the Cd(II) ions leading to a 1-D chain containing chelating L − units in the side chain.

A tetranuclear complex [Zn4(L)4(μ 2-L)2(OH)2(H2O)6] (1) and a trinuclear complex [Zn3(μ 2-L)6(H2O)2] (2) have been prepared by treatment of HL (HL = 3-(4-carboxyphenylhydrazono)pentane-2,4-dione) with ZnCl2· 2H2O or Zn(NO3)2· 6H2O in methanol solution, respectively. Both molecular structures have been characterized by means of elemental analysis, IR and single crystal X-ray diffraction. Their thermal behaviors and fluorescent properties also have been studied.

One novel Pb(II) coordination polymer formulated as [Pb(4-PyCOO)2]n (1) (Py = C5H4N) has been hydrothermally synthesized. The molecular structure of the polymer has been characterized by elemental analysis, IR and single crystal X-ray diffraction. The complex possesses three-dimensional solid-state structure. The thermal property of the complex has been determined.

The first type II intramolecular [5 + 2] cycloaddition reaction involving an oxopyrylium ylide and a simple alkene provides a range of bridged cycloheptenone derivatives.