Approaches to the assembly of the antifungal agent FR-900848: studies on double asymmetric cyclopropanation and an X-ray crystallographic study of (1R,2R)-1,2-bis-[(1S,2S)-2-methylcyclopropyl]-1,2-ethanediyl 3,5-dinitrobenzoate

Abstract

Double asymmetric Simmons-Smith cyclopropanation and Whitham elimination were used to prepare ( 8-1,2-bis-[ ( 1 S,2 S)-2-met h y lcyclo p ro py I let hene, the d icycl o p ro py I et h en e u nit of FR-900848.

Functionalization of Isobutylene Oligomers and 1,2-Polybutadiene with Methyldiazoacetate in the Presence of Cu(OAc)2-2,4-Lut-ZnCl2 Catalytic System

“…The presence of cyclopropane characteristic signals of an ester group and cyclopropane ring in the 1 H, 13 C NMR and IR spectra of compound 6 testified to the introduction of the cyclopropane fragments on the C=C bond into the macromolecule structure (Table 1) The UV-spectrum of polymer 6 differs from that of starting polybutadiene 3 that testified the presence of several chromophor groups in its macromolecule. The differential absorption spectrum of the polymer solutions reduced to the same concentration [3] = [6] = 0.417g/l ( Fig. 1, curve 3 obtained via the subtraction of curve 1 from curve 2) shows three absorption maxima: λ 1 = 274 nm, λ 2 = 257 nm and λ 3 = 223.8 nm.…”

“…The polyene structures containing conjugated cyclopropane cycles are of great interest. For example, polycyclopropane derivatives of fatty acids isolated from Streptoverticillum fervens and Strepfomyces, relate to antibiotics and are inhibitors of albuminous transfer of cholecteryl ether [3].…”

Assembly of the antifungal agent FR-900848 and the CETP inhibitor U-106305: studies on remarkable multicyclopropane natural products

“…The isolated alkene unit of FR-900848 1 was established to be trans by the following experiments (Scheme 8). [30][31][32] Double Simmons-Smith cyclopropanation of alkene 47 proceeded with excellent diastereoselectivity to provide only a single C 2 -symmetric dicyclopropane 48 (89%). Sequential acidmediated deprotection (63%) and condensation with benzaldehyde (64%) gave the benzylidene derivative 50.…”

“…Clearly this stereochemical assignment is fragile unless the structures of the acetals 50 and 53 are secure. This insurance was underwritten by single crystal X-ray crystal structures 30,31 for both 3,5-dinitrobenzoate diesters derived from diols 49 and 52.…”

Cu(OAc)2-2,4-Lut-ZnCl2 – Efficient Catalyst of Functionalization of Isobutylene Oligomers and 1,2-Polybutadiene with Methyldiazoacetate

“…Polymers with structures containing cyclopropane rings together with unsaturated bonds are of particular interest. For example, polycyclopropane derivatives of fatty acids isolated from Streptoverticillum fervens and Strepfomyces belong to antibiotics and inhibit the albuminous transfer of cholecteryl ether [3].…”