A new approach to (+)-anisomycin

An efficient approach to enantiomerically pure (+)-deacetylanisomycin 2a and a formal synthesis of (+)-anisomycin 2 (11% overall yield in 10 steps) have been achieved through simple and good yielding reactions, starting from 1,2:3,4:5,6-tri-O-isopropylidene-d-mannitol 3. Grignard reaction and intramolecular cyclisation reactions are key steps in the strategy.

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2,3:4,5-Di-O-isopropylidene-d-arabinitolC11H20O5[α]D25=-1.1 (c 1.14, CHCl3)Source of chirality: d-mannitolAbsolute configuration: (2R,3S,4R)

1-O-Benzyl-2,3:4,5-Di-O-isopropylidene-d-arabinitolC18H26O5[α]D25=+6.1 (c 0.95, CHCl3)Source of chirality: d-mannitolAbsolute configuration: (2R,3S,4R)

1-O-Benzyl-2,3-O-isopropylidene-d-arabinitolC15H22O5[α]D25=-1.4 (c 1.065, CHCl3)Source of chirality: d-mannitolAbsolute configuration: (2R,3R,4R)

1-O-Benzyl-2,3-O-isopropylidene-4-oxiranyl-d-arabinitolC15H20O4[α]D25=-4.0 (c 0.22, CHCl3)Source of chirality: d-mannitolAbsolute configuration: (2R,3R,4R)

(2R,3R,4R)-1-O-Benzyl-2,3-O-isopropylidene-5-(4-methoxyphenyl) pentane-1,2,3,4-tetrolC22H28O5[α]D25=+13.2 (c 0.68, CHCl3)Source of chirality: d-mannitolAbsolute configuration: (2R,3R,4R)

(2R,3R,4S)-4-Azido-1-O-benzyl-2,3-O-isopropylidene-5-(4-methoxyphenyl) pentane-1,2,3-triolC22H27N3O4[α]D25=+16.9 (c 0.69, CHCl3)Source of chirality: d-mannitolAbsolute configuration: (2R,3R,4S)

(2R,3R,4S)-1-O-Benzyl-4-(tert-butoxycarbonyl)amino-2,3-O-isopropylidene-5-(4-methoxyphenyl) pentane-1,2,3-triolC27H37NO6[α]D25=-4.3 (c 0.33, CHCl3)Source of chirality: d-mannitolAbsolute configuration: (2R,3R,4S)

(2R,3R,4S)-4-(tert-Butoxycarbonyl)amino-2,3-O-isopropylidene-5-(4-methoxyphenyl) pentane-1,2,3-triolC20H31NO6[α]D25=-11.5 (c 0.3, CHCl3)Source of chirality: d-mannitolAbsolute configuration: (2R,3R,4S)

(2S,3R,4R)-N-Benzyloxycarbonyl-3,4-dihydroxy-2-(4-methoxybenzyl) pyrrolidineC12H17NO3[α]D25=+7.9 (c 0.45, MeOH)Source of chirality: d-mannitolAbsolute configuration: (2S,3R,4R)