Asymmetric cyclization processes using unsaturated nitro compounds

A process of forming a compound of general formula (33)

• wherein R1 and R2 are independently from one another one of a silyl group, an aliphatic group and an alicyclic group with a main chain having 1 to about 20 carbon atoms and 0 to about 7 heteroatoms selected from the group consisting of N, O, S, Se and Si,
• R3 is one of H, a silyl group, an aliphatic group, an alicyclic group, an aromatic group, an arylaliphatic group and an arylalicyclic group with a main chain having 1 to about 20 carbon atoms and 0 to about 7 heteroatoms selected from the group consisting of N, O, S, Se and Si, and
• R4 is one of (i) the group —CH═CH—R9, wherein R9 is one of H, a silyl group, an aliphatic group, an alicyclic group, an aromatic group, an arylaliphatic group and an arylalicyclic group with a main chain having 1 to about 20 carbon atoms and 0 to about 7 heteroatoms selected from the group consisting of N, O, S, Se and Si, (ii) an aromatic group, (iii) an arylaliphatic group and (iv) an arylalicyclic group, the aromatic, arylaliphatic or arylalicyclic group comprising a main chain having 1 to about 20 carbon atoms and 0 to about 7 heteroatoms selected from the group consisting of N, O, S, Se and Si,
• the process comprising:
• providing a first compound of the general formula (1),
• providing a second compound of the general formula (2)
• contacting the first compound of formula (1) and the second compound of formula (2) in the presence of a compound of general formula (X),
• wherein R6 is one of H, OMe, OH, OTf, SH, and NH2, R7 is one of OH and —N(R8)H,
• wherein R8 is one of H, a carbamoyl group, and a thiocarbamoyl group and
• represents one of a single and a double bond, and
• allowing the first and the second compound to undergo a reaction for a sufficient period of time to allow the formation of a compound of general formula (23)