Lipase-catalyzed resolution of stereogenic centers in steroid side chains by transesterification in organic solvents: the case of a 26-hydroxycholesterol

Substrate analog studies of the ω-regiospecificity of Mycobacterium tuberculosis cholesterol metabolizing cytochrome P450 enzymes CYP124A1, CYP125A1 and CYP142A1

“…${false[‡false]}_{\text{D}}^{24}$−12.9 ( c 0.38, CHCl 3 ). Synthesis of (20 R )- 19 via a different synthetic route has been reported, 50,51 and the 1 H and 13 C NMR spectral data obtained here are consistent with the limited data available in the literature. 50 1 HNMR (400 MHz, CDCl 3 ): δ 0.03 (s, 6H, ROSi(C H 3 ) 2 C(CH 3 ) 3 ), 0.65 (s, 3H, H 3 -18), 0.80–1.27 (m, 24H, incl.…”

Preparative biotransformations

“…The diastereomer with the (R)-configuration next to the alcohol unit is less reactive. 81 Similarly the diastereomers 49 yield the (S,S)-acetate and recovered (R,S)alcohol (36% yield, 98% ee) on treatment with lipase PS in isopropyl ether containing isopropenyl acetate over 17 h. The alcohol was used as a precursor to pseudopterosins. 82 In general, kinetic resolutions have been achieved by conducting enzyme-catalysed esterifications on primary alcohols where the alcohol moiety is attached directly to a ring system.…”

Steroids: reactions and partial synthesis (1998)

“…The use of Pseudomonas cepacia lipase for the selective acylation of the 25S isomer (25RS)-26hydroxycholesterol has been reported. 190 The potential antifungal activity through the inhibition of ergosterol biosynthesis shown by a series of lanosterol and cholesterol derivatives with modified side chains has been examined. 191 The synthesis of marine sterols with polyhydroxylated side chains has continued to attract interest.…”