Skelly solves

The residue was redissolved in methylene chloride and chromatographed over 500 g of Florisil anhydrous magnesium silicate. The column was eluted with 1 liter portions of hexanes (Skelly-solve B) containing increasing proportions of acetone. There was so eluted 6a-fIuoro-9/3,1113-epoxy-16a-methy 1-17a,21 -d I hydroxy-1, 4-pregnad ene-3,20-dione-21-acetate which was freed of solvent by evaporation of the eluates. 

The mycelium (56 g dry weight) was filtered off and the steroidal material was extracted with methylene chloride, the methylene extracts evaporated to dryness, and the resulting residue chromatographed over a Florisil column. The column was packed with 200 g of Florisil and was developed with five 400-ml fractions each of methylene chloride, Skelly-solve 8-acetone mixtures of 9 1, 8 2, 7 3, 1 1, and methanol. The fraction eluted with Skellysolve 8-acetone (7 3) weighed 1.545 g and on recrystallization from acetone gave, in three crops, 928 mg of product of MP 210° to 235°C. The sample prepared for analysis melted at 245° to 247°C. 

After evacuation, standard vacuum techniques are used to measure and condense equimolar amounts (20 mmoles each) of carbonyl fluoride and oxygen difluoride into the cylinder. The cylinder should be equipped with an explosion rupture assembly and should be in a shielded location before it is allowed to warm up. The valve is then closed, and the cylinder and its contents are allowed to warm to room temperature and remain at that temperature for 5 days. After this time, the cylinder contents are passed through a trap kept at approximately — 140°C. (melting Skelly-Solve F or methylcyclopentane). 

A solution containing2.0 g (0.011 mol) of 3-ethoxy-l//-isoindol-l-onc, 4.0 g (0.045 mol) of 1,1-dimethoxy-ethylene in 140 mL of r-BuOH (distilled from sodium) isirradiated for 30 min under N, in a Pyrex immersion well with a 450-W mercury lamp. Rotary evaporation of the solvent and excess dimethoxyelhylene yields 1.8 g of an impure solid. Recrystallization from Skelly solve B affords the oxetane yield 1.5 g (50 %) mp 62-65 °C. 

Diacetate, QmiHjjFjO, V J4865, Dermaflor, Difrai, Flo-rone, Maxtjtor, Soriftor. Crystals from ethyl acetate-Skelly-solve C and acetone-methanol, mp 221 -223 (dec), uv max (ale) 238 nm (e 17250). [a]p +61 (chloroform). 

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