Microbiologically-assisted hemisynthesis of 1α-hydroxydrimenol

The hemisynthesis of 1α-hydroxydrimenol has been selected to illustrate a synthetic route involving an initial microbial 3β-hydroxylation of a drimenol derivative followed by a functionalization transfer to position 1α, thus generating a new potentially bioactive hydroxylated terpenic compound. Several methods have been investigated for the protection and the regeneration of the 7,8-double bond of drimenyl derivatives.

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(−)-3β-Hydroxy-7α,8α-isopropylidenedioxy-11-acetoxydrimaneC20H34O5[α]D21=−23 (c 2.0, MeOH)Source of chirality: natural (−)-drimenolAbsolute configuration: (3S,5S,7R,8S,9S,10S)

(−)-7α,8α-Isopropylidenedioxy-11-acetoxydrim-2-eneC20H32O4[α]D21=−10.9 (c 2.0, MeOH)Source of chirality: natural (−)-drimenolAbsolute configuration: (5S,7R,8S,9S,10S)

(+)-1α-Hydroxy-7α,8α-isopropylidenedioxy-11-acetoxydrim-2-eneC20H32O5[α]D22=+53 (c 1.98, MeOH)Source of chirality: natural (−)-drimenolAbsolute configuration: (1S,5S,7R,8S,9S,10S)

(+)-1α,11-Diacetoxy-7α,8α-isopropylidenedioxydrim-2-eneC22H36O6[α]D22=+155 (c 1.546, CHCl3)Source of chirality: natural (−)-drimenolAbsolute configuration: (1S,5S,7R,8S,9S,10S)

(+)-1α,11-Diacetoxy-7α,8α-isopropylidenedioxydrimaneC22H38O6[α]D22=+9.3 (c 1.92, MeOH)Source of chirality: natural (−)-drimenolAbsolute configuration: (1S,5S,7R,8S,9S,10S)

(−)-1α,11-Diacetoxy-7α,8α-isopropylidenedioxydrimaneC20H34O5[α]D22=−3.6 (c 1.66, MeOH)Source of chirality: natural (−)-drimenolAbsolute configuration: (1S,5S,7R,8S,9S,10S)

(+)-1α,11-Diacetoxy-7α,8α-dihydroxydrimaneC19H32O6[α]D22=+4.2 (c 2.055, MeOH)Source of chirality: natural (−)-drimenolAbsolute configuration: (1S,5S,7R,8S,9S,10S)

(+)-1α,11-Diacetoxy-drim-7-eneC19H30O4[α]D25=+64.6 (c 1.98, MeOH)Source of chirality: natural (−)-drimenolAbsolute configuration: (1S,5S,9S,10S)

(+)-1α,11-Dihydroxydrim-7-eneC15H26O2[α]D25=+23.1 (c 1.25, MeOH)Source of chirality: natural (−)-drimenolAbsolute configuration: (1S,5S,9S,10S)