Bühler (Austria)

SUMMARY The discussion of preschool fostering of three to six-year old children centres on the aspects of education and care. The Charlotte Bühler-Institute for Practice-Oriented Early Childhood Research conducted an Austrian-wide kindergarten study to investigate the conditions in kindergarten which foster or hamper development. A integral part of this study addressed the question: what functions do the Austrian kindergarten teachers ascribe to the kindergarten in the present socio-economic conditions. From the perspective of kindergarten teachers, the results clearly document that kindergarten is no longer seen as merely an education-providing institution. Though one half of all kindergarten teachers continue to recognise the double mandate of education and care, one fourth of kindergarten teachers consider it as the main task of kindergarten to act as a substitute for family care. Frustration has reached such a level that one fifth of kindergarten teachers claim that kindergarten has neither an educational nor a care function.

Photochemical and non‐photochemical A/D‐secocorrin→corrin‐cyclizations of 19‐carboxy‐ and 19‐formyl‐1‐methylidene‐1,19‐secocorrinates. Decarboxylation (and deformylation) of nickel(II)‐19‐carboxy‐(resp. 19‐formyl)‐corrinatesNickel (II) 1‐methylidene‐2,2,7,7,12,12‐hexamethyl‐15‐cyano‐19‐carboxy‐1,19‐secocorrinate can be induced to cyclize with concomitant decarboxylation to the corresponding corrinate (Scheme 9). Experiments with deuterated derivatives (Scheme 10) indicate that in this decarboxylative A/D‐secocorrin→corrin‐cyclization the ring closure step precedes decarboxylation. In accord therewith is the finding that the corresponding intermediate nickel(II) 19‐carboxy‐corrinate (synthesized via photochemical cyclization of the corresponding cadmium complex, Schemes 6 and 9) decarboxylates under very mild conditions.Nickel(II) 1‐methylidene‐2,2,7,7,12,12‐hexamethyl‐15‐cyano‐19‐formyl‐1,19‐secocorrinate cyclizes smoothly to the corresponding 19‐formyl‐corrinate in the presence of acetic acid/triethylamine. The formyl group of the cyclization product can be eliminated hydrolytically in essentially quantitative yield by treatment with 2N KOH in ethanolic solution (Scheme 11). The non‐photochemical (A→D)‐cyclization of 19‐formyl‐1,19‐secocorrinoids represents formation of the corrin chromophore at the oxidation level of porphyrinogens and exemplifies how a C1‐fragment that eventually leaves the ligand can fulfill a specific function in the (A→D)‐ring closure to a corrin.