Simple synthesis of 4-hydroxycyclohexanone

Abstract

± )-laH,SaH-Tropane-2/3,3/3-diol 2-Benzoate 3-Acetate (11).Method A (from the 3-Acetate).-A solution of 0.80 g (4 mmol) of (± )-l«H,5a:.H-tropane-2,8,3/3-diol 3-acetate (12) in 5 ml of CjHsN was treated with 0.91 g (4 mmol) of benzoic anhydride at room temperature overnight. The usual work-up afforded 1.1 g of oily residue. Chromatography on four silica preparative plates using 50:47:3 Et20-pentane-i'-PrNH2 (R¡ 0.36) followed by recrystallization from hexane gave 0.50 g of poorly formed crystals of 2-benzoate 3-acetate 11, mp 91-95°. From wet ether, 11 formed a hydrate as beautiful, massive prisms which reverted to an oil when dried in vacuo.The air-dried prisms melted at 90-102°with bubbling and their nmr spectrum showed an excess of two hydrogens, presumably from H20. The mass spectrum gave a molecular ion peak at m/e 303 with abundant ions at m/e 244 (M+ -OAc), 198 (M+ -OBz), and 105 (OBz), and very intense peaks at m/e 17 (OH) and 18 (H20).

Total Synthesis of Aeruginosin 98B

“…Birch reduction 11 followed by TIPS silylation of the resultant alcohol provided methyl enol ether in 97% overall yield. Dihydroxylation of methyl enol ether provided a 2:1 mixture of α-hydroxyketones 13a and 13b .…”

“…The allyl carbonates 9a and 9b were prepared from 4-methoxyphenol ( 12 ) (Scheme ). Birch reduction followed by triisopropylsilyl (TIPS) protection of the resultant alcohol provided the corresponding methyl enol ether in 97% overall yield. Dihydroxylation of the methyl enol ether provided a 2:1 mixture of α-hydroxyketones 13a and 13b .…”

A Synthetic Approach To Cadinane- and Amorphane-Type Sesquiterpenoids via Annelation Of Cyclohexanone Derivatives With (E)-2-Methyl-3-hepten-5-one. A Simple Synthesis of (±)-Cadinene Dihydrochloride

“…14a) was an axial-axial coupling. If the HI-H, coupling had been axial-equatorial, the H, transitions would have been spread over only [22][23][24][25] Hz, at most. These facts clearly showed that the lithium-ammonia reduction of the major annelation product (12) had not produced a cis-fused decalone, which would have had the conformation shown in 15.…”