Stereoselective total synthesis of cryptomoscatone E1

The stereoselective total synthesis of cryptomoscatone E1 has been accomplished. The strategy involves Carreira’s asymmetric alkynylation and olefin cross-metathesis reactions as key steps.

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(3R,5R)-5-((tert-Butyldiphenylsilyl)oxy)-1-phenyloct-7-en-1-yn-3-olC30H34O2Si[α]D28 = +15.9 (c 0.36, CHCl3)Absolute configuration: (3R,5R)Source of chirality: Keck allylation

(3R,5R,E)-5-((tert-Butyldiphenylsilyl)oxy)-1-phenylocta-1,7-dien-3-olC30H36O2Si[α]D28 = +35.3 (c 0.23, CHCl3)Absolute configuration: (3R,5R,E)Source of chirality: Keck allylation

(4R,6R)-4-Allyl-2,2-dimethyl-6-((E)-styryl)-1,3-dioxaneC17H22O2[α]D28 = +20 (c 0.2, CHCl3)Absolute configuration: (4R,6R,E)Source of chirality: Keck allylation

(R)-6-((E)-3-((4R,6R)-2,2-Dimethyl-6-((E)-styryl)-1,3-dioxan-4-yl)prop-1-en-1-yl)-5,6-dihydro-2H-pyran-2-oneC22H26O4[α]D28 = −40.6 (c 0.15, CHCl3)Absolute configuration: (R,4R,6R,E,E)Source of chirality: Keck allylation

(R)-6-((1E,4R,6R,7E)-4,6-Dihydroxy-8-phenylocta-1,7-dien-1-yl)-5,6-dihydro-2H-pyran-2-oneC19H22O4[α]D28 = +30.9 (c 0.1, CHCl3)Absolute configuration: (R,1E,4R,6R,7E)Source of chirality: Keck allylation