887. Terpene synthesis. Part I. Alkylation with benzyloxymethyl chloride as a method of introducing a hydroxymethyl group

A new route to furanoeremophilane sesquiterpenoids. Synthesis of Senecio metabolites (±)-6-hydroxyeuryopsin, (±)-1,10-epoxy-6-hydroxyeuryopsin, (±)-toluccanolide A and (±)-toluccanolide C

“…A more direct method for introducing the hydroxymethyl substituent of 20 was therefore sought, and for this purpose we returned to ketone 13. Enolate alkylation with benzyl chloromethyl ether has been found to be a valuable tactic for introducing a hydroxymethyl substituent 20 but our initial results with this reagent using potassium hexamethyldisilazide as the base in a hexane-THF mixture were unpromising, the major product from 13 being O-alkylated material. A similar outcome prevailed when lithium hexamethyldisilazide in THF was used as a base, but when the solvent was changed to toluene a dramatic reversal took place and C-alkylation of 13 was the sole result.…”

Synthesis of stereoisomeric 4-hydroxymethyl-4-methyl-3.beta.-hydroxycholestanes, -androstanes, and -10-methyl-trans-decalins

“…Anal. Caled for C22H3403: Recrystallization twice from ether gave 0.093 g (36%) of pure 25: mp 146-147°; ir 1740 and 1705 cm'1; NMR 0.73 (s, 3, H3Ci8-), 1.08 (s, 3, 10/S-H3C-), 1.37 4a-Carbomethoxy-4/8,10/9-dimethyl-trans-decal-3-one (27) and 4/8-Carbomethoxy-4a,10/3-dimethyl-trans-decal-3-one (28). Methylation of /3-keto ester 13 was conducted in exactly the same manner as methylation of 12, except that tlhe reaction was allowed to proceed for an additional 1 hr.…”

“…4a-Carbomethoxy-4|8,10|8-dimethyl-traris-decal-3d-ol (41). Reduction of 0.399 g (1.7 mmol) of 27 with NaBH4 in exactly the same manner as 12 afforded 0.411 g of crude oily product which was purified by preparative TLC, using 2:1 hexane-ether twice, to afford 0.088 g (21%) of material tentatively identified as 4«-carbo-' methoxy-4/3,10/3-dimethyl-trarcs-decal-3a-ol, 0.29 g (72%) of 41, and 0.020 (5%) of polar material, presumably diol. Compound 41 was sublimed thrice at 70°( 15 mm) to yield 0.150 g (37%) of white needles: mp 87-88°; ir 3400 and 1740 cm-1; NMR 0.95 (s, 3,10/3-H3C-), 1.10 (s, 3, 4/3-H3C-), 3.66 (s, 3, H3COOC-), and 4.00 ppm (br t, 1, 3a-H).…”

The Synthesis of Delphinine: A Stereoselective Total Synthesis of an Optically Active Advanced Relay Compound

“…This compound was converted by the Stork pyrrolidine-enamine procedure (5) to the ally1 tetralone 6' in a yield of 89%. A second alkylation with benzyl chloromethyl ether (6) and sodium hydride in benzene gave 70% of the geminally disubstituted tetralone 7 after purification by chromatography. Compound 7 was subjected to a catalytic osmylation with osmic acid -sodium chlorate in 'All spectral data and properties of all compounds are recorded in the Experimental.…”