Stereochemistry in the reactions of (Z)- and (E)-allyltributylstannyl reagents with quinones

Temporal relationship between inositol polyphosphate formation and increases in cytosolic Ca2+ in quiescent 3T3 cells stimulated by platelet-derived growth factor, bombesin and vasopressin.

“…Bombesin stimulated the formation of Ins(1,4,5)P3 and subsequently of Ins(1,3,4)P3 and InsP2 within seconds of their addition. These results agree with reports using 3T3 cells attached to dishes and incubated in the absence of fura 2 (Heslop et al, 1986;Takuwa et al, 1987). A similar result was obtained when the cells were challenged with vasopressin instead of bombesin.…”

“…While the inositol-triphosphate (InsP3) and InsP2 pools reached an equilibrium after 1-2 min ( Figure IA), the inositolmonophosphate (InsP) fraction continued to accumulate over a period of 5-10 min ( Figure 2). These results are consistent with reports using 3T3 cells attached to dishes and incubated in the absence of fura 2 (Heslop et al, 1986;Takuwa et al, 1987). The concomitant increase in Ins(1,4,5)P3 and [Ca2 ]cyt shown in Figure 1 is consistent with the role of Ins(1,4,5)P3 as a second messenger mediating the Ca2+ mobilization induced by bombesin.…”

“…The addition of these mitogens causes a transient rise of cytosolic Ca2+ concentration ([Ca2+]cyt), increases the rate of Ca2+ efflux from radiolabelled cells and markedly decreases total Ca2+ content of the cell. Although these mitogens bind to different receptors in Swiss 3T3 cells (Rozengurt, 1986;Collins and Rozengurt, 1983;Rozengurt, 1985, 1987a,b) the mobilization of intracellular Ca2+ may be mediated by inositol 1,4,4,5)P3] which has been proposed as a second messenger in the action of many ligands that induce receptor-mediated inositol lipid turnover and Ca2 + mobilization Majerus et al, 1986) including PDGF, bombesin and vasopressin Hasegawa-Sasaki, 1985;Heslop et al, 1986;Takuwa et al, 1987).…”

Allylation of Aldehydes Promoted by the Cerium(III) Chloride Heptahydrate/Sodium Iodide System: the Dependence of Regio‐ and Stereocontrol on the Reaction Conditions

“…[10] In conclusion, the synthesis of a (Z)-allyl alcohol is still an unsolved problem. [11] During our program to develop new synthetic uses of the CeCl 3 · 7 H 2 O/NaI [12] combination in promoting C À C bond formation, [13] we found that this system strongly facilitates the addition of allyltributylstannane to aldehydes in CH 3 CN. [14] We report now that by this protocol a highly regio-and stereoselective addition of the 2-alkenyltributyltin derivative is accomplished surprisingly leading to the prevalent formation of the a-adduct in the less stable (Z)-configuration.…”

Bismuth-Mediated Organic Reactions

“…The allylation of quinones is generally carried out with allylsilanes using acid catalysts such as titanium tetrachloride and lithium perchlorate in diethyl ether (LPDE) [157,158]. Other methods involve the addition of allyl indium, allyl magnesium, allyl nickel complexes, or allylstannane to the quinones [159][160][161][162][163][164]. Other methods involve the addition of allyl indium, allyl magnesium, allyl nickel complexes, or allylstannane to the quinones [159][160][161][162][163][164].…”