Abstract: Chroman derivatives of the formula I in which R1 is acyl having 1-6 C atoms, —CO—R5 or an amino protective group, R2 is H or alkyl having 1-6 C atoms, R3, R4 in each case independently of one another are H, alkyl having 1-6 C atoms, CN, Hal or COOR2, R5 is phenyl which is unsubstituted or mono- or disubstituted by alkyl having 1-6 C atoms, OR2 or Hal, X is H, H or O, Hal is F, Cl, Br or I, and their salts, are suitable as intermediates in the synthesis of medicaments.

Abstract: The invention relates to a process for the preparation of cyclohexanones from the corresponding phenols by partial hydrogenation, characterized in that the reaction mixture obtained by means of the hydrogenation is treated with sulfonating agents before the isolation of the cyclohexanone.

Abstract: The invention relates to a liquid-crystalline medium based on a mixture of polar compounds having positive dielectric anisotropy, characterized in that it comprises one or more compounds of the formula I ##STR1## and one or more compounds of the formula I.sup.* ##STR2## in which R, Y, L and s are as defined herein.

Abstract: The invention relates to a wheelchair having a frame, a seat, a backrest, wheels and attachments fixed to the frame, characterized in that colored cladding parts can be detachably fixed, particularly by plug or clamp connections, to substantially any part or component of the wheelchair. This makes it possible in a simple and inexpensive manner to bring about a variable color design for the overall wheelchair. The cladding parts are preferably constructed as flat plastic parts which can be locked by means of projections formed in or on the cladding parts into corresponding recesses in the wheelchair or can be slid into longitudinal grooves in the frame of the wheelchair.

Abstract: A wheelchair with two facing, interconnected, adjustable sideframes having fit thereto a seat, backrest, driving wheels and guide wheels is described. The wheelchair is characterized in that each sideframe has two rigid frame parts, which are adjustably interconnected in the longitudinal direction of the wheelchair by elongated frame sections. On one rigid frame part of each sideframe can be fit one of the driving wheels and on the other rigid frame part of each sideframe one of the guide wheels. The wheelchair frame is readily longitudinally adjustable. Simultaneously with the adjustment of the seat position, there is an adjustment of the wheels so that an optimum weight distribution over the wheelchair wheels is maintained. The frame has an extremely high rigidity.

Abstract: The present invention relates to a seat structure for collapsible (foldable) invalid chairs provided with a flexible seat and/or back covering, comprising an upholstery material (3) and a covering material (4) at least partially enclosing said upholstery material. The covering material (4) is provided with ultrafine perforations, and an open-pore foam material shaped as a molded part is used for the upholstery material.