BFGS

The BFGS formula differs from the DFP equation by an additional term ... 

Techniques used to find global and local energy minima include sequential simplex, steepest descents, conjugate gradient and variants (BFGS), and the Newton and modified Newton methods (Newton-Raphson). 

BFG samples unannealed, Dow (Upjohn) and Mobay samples annealed 16 hr at 240°F. 

The influence of the conformational factors, which play a decisive role in directing oxide fission in the above cases is no longer operative in the case of 3-keto-5a,6a-epoxides and their 3-ethylene ketals. With these substrates the —I effect of the BFs-complexed 3-keto or 3-ketal grouping predominates leading to the fluorohydrins. Thus, treatment of both 5a,6a-oxidopregnane-3,20-dione (35) and its 3,20-bisethylene ketal with BFg-etherate in benzene-ether affords in 45% yield the 6jff-fluoro-5a-hydroxy-derivative (36) and its 3-ethylene ketal, respectively. which are converted into the 6a-fluoro-A -CH3... 

PRODUCT BFG.xls consists of the chemist s table, a reduced table obtained by casting out data that is not ammenable to statistical analysis such as subjective assessments ( off-white color, characteristic crystal form, pungent smell STEP 1), and the final table that was freed of all inconsistencies by going back to the original data (STEP 2). Various interesting items are highlighted ... 

Table 4.39. Excerpt from Trend Analysis Table for Product BFG ... 

The alkaline solution containing 2,4-D and 2,4,5-T residues was acidified and extracted with diethyl ether. NH4OH (0.1 ml) was added to the extract which was then taken to dryness. The residue was butylated with 14% BCI3 in n-BuOH following the concentrated-BFg method described by Woolson and Harris (2). 

Maschmeyer T, Klunduk MC, Martin CM, Shephard DS, Thomas JM, Johnson BFG (1997) Chem Commun 1847... 

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