Flippin-Lodge angle

Figure 4.9. (a) Deviation of the attack trajectory from the normal plane in the reaction of hydride with pivaldehyde. Reprinted with permission from ref. [25], copyright 1987, American Chemical Society, (b) Newman projection of a ketone, with an approaching nucleophile, and the Flippin-Lodge angle of deviation from the normal plane, away from the larger substituent, R (after ref. [27]). 

Fig. 6.39. a Attack of hydride on pivalaldehyde [(CH3)3CC(=0)H], deviation of the attack trajectory from the plane normal to the carbonyl plane and passing through C=0 b definition of the Flippin-Lodge angle [Pg.272]

The same angles, the Burgi-Dunitz and the Flippin-Lodge, will have their counterparts for nucleophilic attack on a C=C bond, but the former at least ought to be muted, because all three factors 5.50-5.52 will be reduced when the oxygen atom of the carbonyl group is replaced by a carbon atom. 

Professor Heathcock named this angle after his two collaborators, Lee Flippin and Eric Lodge... 

---